From: Anthony Liguori <anthony@codemonkey.ws>
To: akataria@vmware.com
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
"avi@redhat.com" <avi@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Gerd Hoffmann <kraxel@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
the arch/x86 maintainers <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Nakajima, Jun" <jun.nakajima@intel.com>,
Daniel Hecht <dhecht@vmware.com>, Zach Amsden <zach@vmware.com>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [RFC] CPUID usage for interaction between Hypervisors and Linux.
Date: Wed, 01 Oct 2008 16:08:47 -0500 [thread overview]
Message-ID: <48E3E6DF.8060400@codemonkey.ws> (raw)
In-Reply-To: <1222894878.9381.63.camel@alok-dev1>
Alok Kataria wrote:
> On Wed, 2008-10-01 at 11:04 -0700, Jeremy Fitzhardinge wrote:
>
> 2. Divergence in the interface provided by the hypervisors :
> The reason we brought up a flat hierarchy is because we think we should
> be moving towards a approach where the guest code doesn't diverge too
> much when running under different hypervisors. That is the guest
> essentially does the same thing if its running on say Xen or VMware.
>
> This design IMO, will take us a step backward to what we already have
> seen with para virt ops. Each hypervisor (mostly) defines its own cpuid
> block, the guest correspondingly needs to have code to handle each of
> these cpuid blocks, with these blocks will mostly being exclusive.
>
What's wrong with what we have in paravirt_ops? Just agreeing on CPUID
doesn't help very much. You still need a mechanism for doing hypercalls
to implement anything meaningful. We aren't going to agree on a
hypercall mechanism. KVM uses direct hypercall instructions, Xen uses a
hypercall page, VMware uses VMI, Hyper-V uses MSR writes. We all have
already defined the hypercall namespace in a certain way.
We've already gone down the road of trying to make standard paravirtual
interfaces (via virtio). No one was sufficiently interested in
collaborating. I don't see why other paravirtualizations are going to
be much different.
Regards,
Anthony Liguori
next prev parent reply other threads:[~2008-10-01 21:10 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-01 17:14 [RFC] CPUID usage for interaction between Hypervisors and Linux Alok Kataria
2008-10-01 17:21 ` H. Peter Anvin
2008-10-01 17:33 ` Alok Kataria
2008-10-01 17:45 ` H. Peter Anvin
2008-10-01 18:06 ` Jeremy Fitzhardinge
2008-10-01 21:05 ` Alok Kataria
2008-10-01 22:46 ` H. Peter Anvin
2008-10-02 1:11 ` Nakajima, Jun
2008-10-02 1:24 ` H. Peter Anvin
2008-10-03 22:33 ` Nakajima, Jun
2008-10-03 23:30 ` H. Peter Anvin
2008-10-04 0:27 ` Nakajima, Jun
2008-10-04 0:35 ` H. Peter Anvin
2008-10-07 22:30 ` Nakajima, Jun
2008-10-07 22:37 ` H. Peter Anvin
2008-10-07 23:45 ` Jeremy Fitzhardinge
2008-10-08 1:09 ` H. Peter Anvin
2008-10-07 23:41 ` Jeremy Fitzhardinge
2008-10-07 23:45 ` H. Peter Anvin
2008-10-08 0:40 ` Jeremy Fitzhardinge
2008-10-04 8:53 ` Avi Kivity
2008-10-01 17:47 ` H. Peter Anvin
2008-10-01 18:04 ` Jeremy Fitzhardinge
2008-10-01 18:07 ` H. Peter Anvin
2008-10-01 18:12 ` Jeremy Fitzhardinge
2008-10-01 18:16 ` H. Peter Anvin
2008-10-01 18:36 ` Jeremy Fitzhardinge
2008-10-01 18:43 ` H. Peter Anvin
2008-10-01 19:56 ` Jeremy Fitzhardinge
2008-10-01 20:38 ` Chris Wright
2008-10-01 22:38 ` H. Peter Anvin
2008-10-01 21:01 ` Alok Kataria
2008-10-01 21:08 ` Anthony Liguori [this message]
2008-10-01 21:15 ` Chris Wright
2008-10-01 21:31 ` Anthony Liguori
2008-10-01 21:23 ` Alok Kataria
2008-10-01 21:29 ` Anthony Liguori
2008-10-01 21:17 ` Jeremy Fitzhardinge
2008-10-01 21:34 ` Anthony Liguori
2008-10-01 21:43 ` Chris Wright
2008-10-02 11:29 ` Avi Kivity
2008-10-01 23:47 ` Zachary Amsden
2008-10-02 0:39 ` H. Peter Anvin
2008-10-02 0:57 ` H. Peter Anvin
2008-10-02 1:11 ` Zachary Amsden
2008-10-02 1:21 ` H. Peter Anvin
2008-10-02 0:41 ` Anthony Liguori
[not found] ` <48E3BBC1.2050607__35819.6151479662$1222884502$gmane$org@goop.org>
2008-10-01 20:03 ` Anthony Liguori
2008-10-01 20:08 ` Jeremy Fitzhardinge
[not found] ` <48E3D8A8.604__13396.6479487301$1222891831$gmane$org@goop.org>
2008-10-01 21:03 ` Anthony Liguori
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